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Commit e1ef4bf2 authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

[IPV4]: Use Protocol Independant Policy Routing Rules Framework 



Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 101367c2

include/net/ip_fib.h

+7 −7
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 


#include <net/flow.h>

#include <linux/seq_file.h>

#include <net/fib_rules.h>



/* WARNING: The ordering of these elements must match ordering

 *          of RTA_* rtnetlink attribute numbers.
@@ -203,9 +204,8 @@ static inline void fib_select_default(const struct flowi *flp, struct fib_result 
#define ip_fib_main_table (fib_tables[RT_TABLE_MAIN])



extern struct fib_table * fib_tables[RT_TABLE_MAX+1];

extern int fib_lookup(const struct flowi *flp, struct fib_result *res);

extern int fib_lookup(struct flowi *flp, struct fib_result *res);

extern struct fib_table *__fib_new_table(int id);

extern void fib_rule_put(struct fib_rule *r);



static inline struct fib_table *fib_get_table(int id)

{
@@ -251,15 +251,15 @@ extern u32 __fib_res_prefsrc(struct fib_result *res); 
extern struct fib_table *fib_hash_init(int id);



#ifdef CONFIG_IP_MULTIPLE_TABLES

/* Exported by fib_rules.c */

extern int fib4_rules_dump(struct sk_buff *skb, struct netlink_callback *cb);



extern void __init fib4_rules_init(void);

extern void __exit fib4_rules_cleanup(void);



extern int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);

extern int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);

extern int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb);

#ifdef CONFIG_NET_CLS_ROUTE

extern u32 fib_rules_tclass(struct fib_result *res);

#endif

extern void fib_rules_init(void);



#endif



static inline void fib_combine_itag(u32 *itag, struct fib_result *res)

net/ipv4/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ config IP_FIB_HASH 
config IP_MULTIPLE_TABLES

	bool "IP: policy routing"

	depends on IP_ADVANCED_ROUTER

	select FIB_RULES

	---help---

	  Normally, a router decides what to do with a received packet based

	  solely on the packet's final destination address. If you say Y here,

net/ipv4/devinet.c

+1 −3
Original line number Diff line number Diff line
@@ -1151,9 +1151,7 @@ static struct rtnetlink_link inet_rtnetlink_table[RTM_NR_MSGTYPES] = { 
	[RTM_GETROUTE - RTM_BASE] = { .doit	= inet_rtm_getroute,

				      .dumpit	= inet_dump_fib,	},

#ifdef CONFIG_IP_MULTIPLE_TABLES

	[RTM_NEWRULE  - RTM_BASE] = { .doit	= inet_rtm_newrule,	},

	[RTM_DELRULE  - RTM_BASE] = { .doit	= inet_rtm_delrule,	},

	[RTM_GETRULE  - RTM_BASE] = { .dumpit	= inet_dump_rules,	},

	[RTM_GETRULE  - RTM_BASE] = { .dumpit	= fib4_rules_dump,	},

#endif

};

net/ipv4/fib_frontend.c

+1 −1
Original line number Diff line number Diff line
@@ -656,7 +656,7 @@ void __init ip_fib_init(void) 
	ip_fib_local_table = fib_hash_init(RT_TABLE_LOCAL);

	ip_fib_main_table  = fib_hash_init(RT_TABLE_MAIN);

#else

	fib_rules_init();

	fib4_rules_init();

#endif



	register_netdevice_notifier(&fib_netdev_notifier);

net/ipv4/fib_rules.c

+239 −366
Original line number Diff line number Diff line
@@ -5,9 +5,8 @@ 
 *

 *		IPv4 Forwarding Information Base: policy rules.

 *

 * Version:	$Id: fib_rules.c,v 1.17 2001/10/31 21:55:54 davem Exp $

 *

 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>

 * 		Thomas Graf <tgraf@suug.ch>

 *

 *		This program is free software; you can redistribute it and/or

 *		modify it under the terms of the GNU General Public License
@@ -19,129 +18,154 @@ 
 *		Marc Boucher	:	routing by fwmark

 */



#include <asm/uaccess.h>

#include <asm/system.h>

#include <linux/bitops.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/sched.h>

#include <linux/mm.h>

#include <linux/string.h>

#include <linux/socket.h>

#include <linux/sockios.h>

#include <linux/errno.h>

#include <linux/in.h>

#include <linux/inet.h>

#include <linux/inetdevice.h>

#include <linux/netdevice.h>

#include <linux/if_arp.h>

#include <linux/proc_fs.h>

#include <linux/skbuff.h>

#include <linux/netlink.h>

#include <linux/inetdevice.h>

#include <linux/init.h>

#include <linux/list.h>

#include <linux/rcupdate.h>



#include <net/ip.h>

#include <net/protocol.h>

#include <net/route.h>

#include <net/tcp.h>

#include <net/sock.h>

#include <net/ip_fib.h>

#include <net/fib_rules.h>



#define FRprintk(a...)

static struct fib_rules_ops fib4_rules_ops;



struct fib_rule

struct fib4_rule

{

	struct hlist_node hlist;

	atomic_t	r_clntref;

	u32		r_preference;

	unsigned char	r_table;

	unsigned char	r_action;

	unsigned char	r_dst_len;

	unsigned char	r_src_len;

	u32		r_src;

	u32		r_srcmask;

	u32		r_dst;

	u32		r_dstmask;

	u32		r_srcmap;

	u8		r_flags;

	u8		r_tos;

	struct fib_rule		common;

	u8			dst_len;

	u8			src_len;

	u8			tos;

	u32			src;

	u32			srcmask;

	u32			dst;

	u32			dstmask;

#ifdef CONFIG_IP_ROUTE_FWMARK

	u32		r_fwmark;

	u32			fwmark;

#endif

	int		r_ifindex;

#ifdef CONFIG_NET_CLS_ROUTE

	__u32		r_tclassid;

	u32			tclassid;

#endif

	char		r_ifname[IFNAMSIZ];

	int		r_dead;

	struct		rcu_head rcu;

};



static struct fib_rule default_rule = {

	.r_clntref =	ATOMIC_INIT(2),

	.r_preference =	0x7FFF,

	.r_table =	RT_TABLE_DEFAULT,

	.r_action =	RTN_UNICAST,

static struct fib4_rule default_rule = {

	.common = {

		.refcnt =	ATOMIC_INIT(2),

		.pref =		0x7FFF,

		.table =	RT_TABLE_DEFAULT,

		.action =	FR_ACT_TO_TBL,

	},

};



static struct fib_rule main_rule = {

	.r_clntref =	ATOMIC_INIT(2),

	.r_preference =	0x7FFE,

	.r_table =	RT_TABLE_MAIN,

	.r_action =	RTN_UNICAST,

static struct fib4_rule main_rule = {

	.common = {

		.refcnt =	ATOMIC_INIT(2),

		.pref =		0x7FFE,

		.table =	RT_TABLE_MAIN,

		.action =	FR_ACT_TO_TBL,

	},

};



static struct fib_rule local_rule = {

	.r_clntref =	ATOMIC_INIT(2),

	.r_table =	RT_TABLE_LOCAL,

	.r_action =	RTN_UNICAST,

static struct fib4_rule local_rule = {

	.common = {

		.refcnt =	ATOMIC_INIT(2),

		.table =	RT_TABLE_LOCAL,

		.action =	FR_ACT_TO_TBL,

		.flags =	FIB_RULE_PERMANENT,

	},

};



static struct hlist_head fib_rules;

static LIST_HEAD(fib4_rules);



#ifdef CONFIG_NET_CLS_ROUTE

u32 fib_rules_tclass(struct fib_result *res)

{

	return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;

}

#endif



int fib_lookup(struct flowi *flp, struct fib_result *res)

{

	struct fib_lookup_arg arg = {

		.result = res,

	};

	int err;



/* writer func called from netlink -- rtnl_sem hold*/

	err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg);

	res->r = arg.rule;



static void rtmsg_rule(int, struct fib_rule *);

	return err;

}



int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)

int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, int flags,

		     struct fib_lookup_arg *arg)

{

	struct rtattr **rta = arg;

	struct rtmsg *rtm = NLMSG_DATA(nlh);

	struct fib_rule *r;

	struct hlist_node *node;

	int err = -ESRCH;



	hlist_for_each_entry(r, node, &fib_rules, hlist) {

		if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) &&

		    rtm->rtm_src_len == r->r_src_len &&

		    rtm->rtm_dst_len == r->r_dst_len &&

		    (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) &&

		    rtm->rtm_tos == r->r_tos &&

#ifdef CONFIG_IP_ROUTE_FWMARK

		    (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&

#endif

		    (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&

		    (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&

		    (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&

		    (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {

			err = -EPERM;

			if (r == &local_rule)

				break;

	int err = -EAGAIN;

	struct fib_table *tbl;



			hlist_del_rcu(&r->hlist);

			r->r_dead = 1;

			rtmsg_rule(RTM_DELRULE, r);

			fib_rule_put(r);

			err = 0;

	switch (rule->action) {

	case FR_ACT_TO_TBL:

		break;



	case FR_ACT_UNREACHABLE:

		err = -ENETUNREACH;

		goto errout;



	case FR_ACT_PROHIBIT:

		err = -EACCES;

		goto errout;



	case FR_ACT_BLACKHOLE:

	default:

		err = -EINVAL;

		goto errout;

	}

	}



	if ((tbl = fib_get_table(rule->table)) == NULL)

		goto errout;



	err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);

	if (err > 0)

		err = -EAGAIN;

errout:

	return err;

}



/* Allocate new unique table id */



void fib_select_default(const struct flowi *flp, struct fib_result *res)

{

	if (res->r && res->r->action == FR_ACT_TO_TBL &&

	    FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {

		struct fib_table *tb;

		if ((tb = fib_get_table(res->r->table)) != NULL)

			tb->tb_select_default(tb, flp, res);

	}

}



static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)

{

	struct fib4_rule *r = (struct fib4_rule *) rule;

	u32 daddr = fl->fl4_dst;

	u32 saddr = fl->fl4_src;



	if (((saddr ^ r->src) & r->srcmask) ||

	    ((daddr ^ r->dst) & r->dstmask))

		return 0;



	if (r->tos && (r->tos != fl->fl4_tos))

		return 0;



#ifdef CONFIG_IP_ROUTE_FWMARK

	if (r->fwmark && (r->fwmark != fl->fl4_fwmark))

		return 0;

#endif



	return 1;

}



static struct fib_table *fib_empty_table(void)

{
@@ -153,329 +177,178 @@ static struct fib_table *fib_empty_table(void) 
	return NULL;

}



static inline void fib_rule_put_rcu(struct rcu_head *head)

{

	struct fib_rule *r = container_of(head, struct fib_rule, rcu);

	kfree(r);

}

static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {

	[FRA_IFNAME]	= { .type = NLA_STRING },

	[FRA_PRIORITY]	= { .type = NLA_U32 },

	[FRA_SRC]	= { .type = NLA_U32 },

	[FRA_DST]	= { .type = NLA_U32 },

	[FRA_FWMARK]	= { .type = NLA_U32 },

	[FRA_FLOW]	= { .type = NLA_U32 },

};



void fib_rule_put(struct fib_rule *r)

static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,

			       struct nlmsghdr *nlh, struct fib_rule_hdr *frh,

			       struct nlattr **tb)

{

	if (atomic_dec_and_test(&r->r_clntref)) {

		if (r->r_dead)

			call_rcu(&r->rcu, fib_rule_put_rcu);

		else

			printk("Freeing alive rule %p\n", r);

	}

}

	int err = -EINVAL;

	struct fib4_rule *rule4 = (struct fib4_rule *) rule;



/* writer func called from netlink -- rtnl_sem hold*/

	if (frh->src_len > 32 || frh->dst_len > 32 ||

	    (frh->tos & ~IPTOS_TOS_MASK))

		goto errout;



int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)

{

	struct rtattr **rta = arg;

	struct rtmsg *rtm = NLMSG_DATA(nlh);

	struct fib_rule *r, *new_r, *last = NULL;

	struct hlist_node *node = NULL;

	unsigned char table_id;



	if (rtm->rtm_src_len > 32 || rtm->rtm_dst_len > 32 ||

	    (rtm->rtm_tos & ~IPTOS_TOS_MASK))

		return -EINVAL;

	if (rule->table == RT_TABLE_UNSPEC) {

		if (rule->action == FR_ACT_TO_TBL) {

			struct fib_table *table;



	if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)

		return -EINVAL;

			table = fib_empty_table();

			if (table == NULL) {

				err = -ENOBUFS;

				goto errout;

			}



	table_id = rtm->rtm_table;

	if (table_id == RT_TABLE_UNSPEC) {

		struct fib_table *table;

		if (rtm->rtm_type == RTN_UNICAST) {

			if ((table = fib_empty_table()) == NULL)

				return -ENOBUFS;

			table_id = table->tb_id;

			rule->table = table->tb_id;

		}

	}



	new_r = kzalloc(sizeof(*new_r), GFP_KERNEL);

	if (!new_r)

		return -ENOMEM;



	if (rta[RTA_SRC-1])

		memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4);

	if (rta[RTA_DST-1])

		memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4);

	if (rta[RTA_GATEWAY-1])

		memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4);

	new_r->r_src_len = rtm->rtm_src_len;

	new_r->r_dst_len = rtm->rtm_dst_len;

	new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len);

	new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len);

	new_r->r_tos = rtm->rtm_tos;

	if (tb[FRA_SRC])

		rule4->src = nla_get_u32(tb[FRA_SRC]);



	if (tb[FRA_DST])

		rule4->dst = nla_get_u32(tb[FRA_DST]);



#ifdef CONFIG_IP_ROUTE_FWMARK

	if (rta[RTA_PROTOINFO-1])

		memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);

	if (tb[FRA_FWMARK])

		rule4->fwmark = nla_get_u32(tb[FRA_FWMARK]);

#endif

	new_r->r_action = rtm->rtm_type;

	new_r->r_flags = rtm->rtm_flags;

	if (rta[RTA_PRIORITY-1])

		memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);

	new_r->r_table = table_id;

	if (rta[RTA_IIF-1]) {

		struct net_device *dev;

		rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);

		new_r->r_ifindex = -1;

		dev = __dev_get_by_name(new_r->r_ifname);

		if (dev)

			new_r->r_ifindex = dev->ifindex;

	}



#ifdef CONFIG_NET_CLS_ROUTE

	if (rta[RTA_FLOW-1])

		memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4);

	if (tb[FRA_FLOW])

		rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);

#endif

	r = container_of(fib_rules.first, struct fib_rule, hlist);



	if (!new_r->r_preference) {

		if (r && r->hlist.next != NULL) {

			r = container_of(r->hlist.next, struct fib_rule, hlist);

			if (r->r_preference)

				new_r->r_preference = r->r_preference - 1;

		}

	}

	rule4->src_len = frh->src_len;

	rule4->srcmask = inet_make_mask(rule4->src_len);

	rule4->dst_len = frh->dst_len;

	rule4->dstmask = inet_make_mask(rule4->dst_len);

	rule4->tos = frh->tos;



	hlist_for_each_entry(r, node, &fib_rules, hlist) {

		if (r->r_preference > new_r->r_preference)

			break;

		last = r;

	err = 0;

errout:

	return err;

}

	atomic_inc(&new_r->r_clntref);



	if (last)

		hlist_add_after_rcu(&last->hlist, &new_r->hlist);

	else

		hlist_add_before_rcu(&new_r->hlist, &r->hlist);

static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,

			     struct nlattr **tb)

{

	struct fib4_rule *rule4 = (struct fib4_rule *) rule;



	rtmsg_rule(RTM_NEWRULE, new_r);

	if (frh->src_len && (rule4->src_len != frh->src_len))

		return 0;

}



#ifdef CONFIG_NET_CLS_ROUTE

u32 fib_rules_tclass(struct fib_result *res)

{

	if (res->r)

		return res->r->r_tclassid;

	if (frh->dst_len && (rule4->dst_len != frh->dst_len))

		return 0;

}

#endif



/* callers should hold rtnl semaphore */



static void fib_rules_detach(struct net_device *dev)

{

	struct hlist_node *node;

	struct fib_rule *r;

	if (frh->tos && (rule4->tos != frh->tos))

		return 0;



	hlist_for_each_entry(r, node, &fib_rules, hlist) {

		if (r->r_ifindex == dev->ifindex)

			r->r_ifindex = -1;

#ifdef CONFIG_IP_ROUTE_FWMARK

	if (tb[FRA_FWMARK] && (rule4->fwmark != nla_get_u32(tb[FRA_FWMARK])))

		return 0;

#endif



	}

}

#ifdef CONFIG_NET_CLS_ROUTE

	if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))

		return 0;

#endif



/* callers should hold rtnl semaphore */

	if (tb[FRA_SRC] && (rule4->src != nla_get_u32(tb[FRA_SRC])))

		return 0;



static void fib_rules_attach(struct net_device *dev)

{

	struct hlist_node *node;

	struct fib_rule *r;

	if (tb[FRA_DST] && (rule4->dst != nla_get_u32(tb[FRA_DST])))

		return 0;



	hlist_for_each_entry(r, node, &fib_rules, hlist) {

		if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)

			r->r_ifindex = dev->ifindex;

	}

	return 1;

}



int fib_lookup(const struct flowi *flp, struct fib_result *res)

static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,

			  struct nlmsghdr *nlh, struct fib_rule_hdr *frh)

{

	int err;

	struct fib_rule *r, *policy;

	struct fib_table *tb;

	struct hlist_node *node;



	u32 daddr = flp->fl4_dst;

	u32 saddr = flp->fl4_src;

	struct fib4_rule *rule4 = (struct fib4_rule *) rule;



FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ",

	NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src));

	frh->family = AF_INET;

	frh->dst_len = rule4->dst_len;

	frh->src_len = rule4->src_len;

	frh->tos = rule4->tos;



	rcu_read_lock();



	hlist_for_each_entry_rcu(r, node, &fib_rules, hlist) {

		if (((saddr^r->r_src) & r->r_srcmask) ||

		    ((daddr^r->r_dst) & r->r_dstmask) ||

		    (r->r_tos && r->r_tos != flp->fl4_tos) ||

#ifdef CONFIG_IP_ROUTE_FWMARK

		    (r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) ||

	if (rule4->fwmark)

		NLA_PUT_U32(skb, FRA_FWMARK, rule4->fwmark);

#endif

		    (r->r_ifindex && r->r_ifindex != flp->iif))

			continue;



FRprintk("tb %d r %d ", r->r_table, r->r_action);

		switch (r->r_action) {

		case RTN_UNICAST:

			policy = r;

			break;

		case RTN_UNREACHABLE:

			rcu_read_unlock();

			return -ENETUNREACH;

		default:

		case RTN_BLACKHOLE:

			rcu_read_unlock();

			return -EINVAL;

		case RTN_PROHIBIT:

			rcu_read_unlock();

			return -EACCES;

		}

	if (rule4->dst_len)

		NLA_PUT_U32(skb, FRA_DST, rule4->dst);



		if ((tb = fib_get_table(r->r_table)) == NULL)

			continue;

		err = tb->tb_lookup(tb, flp, res);

		if (err == 0) {

			res->r = policy;

			if (policy)

				atomic_inc(&policy->r_clntref);

			rcu_read_unlock();

	if (rule4->src_len)

		NLA_PUT_U32(skb, FRA_SRC, rule4->src);



#ifdef CONFIG_NET_CLS_ROUTE

	if (rule4->tclassid)

		NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);

#endif

	return 0;

		}

		if (err < 0 && err != -EAGAIN) {

			rcu_read_unlock();

			return err;

		}

	}

FRprintk("FAILURE\n");

	rcu_read_unlock();

	return -ENETUNREACH;

}



void fib_select_default(const struct flowi *flp, struct fib_result *res)

{

	if (res->r && res->r->r_action == RTN_UNICAST &&

	    FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {

		struct fib_table *tb;

		if ((tb = fib_get_table(res->r->r_table)) != NULL)

			tb->tb_select_default(tb, flp, res);

	}

nla_put_failure:

	return -ENOBUFS;

}



static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)

int fib4_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct net_device *dev = ptr;



	if (event == NETDEV_UNREGISTER)

		fib_rules_detach(dev);

	else if (event == NETDEV_REGISTER)

		fib_rules_attach(dev);

	return NOTIFY_DONE;

	return fib_rules_dump(skb, cb, AF_INET);

}





static struct notifier_block fib_rules_notifier = {

	.notifier_call =fib_rules_event,

};



static __inline__ int inet_fill_rule(struct sk_buff *skb,

				     struct fib_rule *r,

				     u32 pid, u32 seq, int event,

				     unsigned int flags)

static u32 fib4_rule_default_pref(void)

{

	struct rtmsg *rtm;

	struct nlmsghdr  *nlh;

	unsigned char	 *b = skb->tail;



	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);

	rtm = NLMSG_DATA(nlh);

	rtm->rtm_family = AF_INET;

	rtm->rtm_dst_len = r->r_dst_len;

	rtm->rtm_src_len = r->r_src_len;

	rtm->rtm_tos = r->r_tos;

#ifdef CONFIG_IP_ROUTE_FWMARK

	if (r->r_fwmark)

		RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);

#endif

	rtm->rtm_table = r->r_table;

	rtm->rtm_protocol = 0;

	rtm->rtm_scope = 0;

	rtm->rtm_type = r->r_action;

	rtm->rtm_flags = r->r_flags;



	if (r->r_dst_len)

		RTA_PUT(skb, RTA_DST, 4, &r->r_dst);

	if (r->r_src_len)

		RTA_PUT(skb, RTA_SRC, 4, &r->r_src);

	if (r->r_ifname[0])

		RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);

	if (r->r_preference)

		RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);

	if (r->r_srcmap)

		RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap);

#ifdef CONFIG_NET_CLS_ROUTE

	if (r->r_tclassid)

		RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid);

#endif

	nlh->nlmsg_len = skb->tail - b;

	return skb->len;

	struct list_head *pos;

	struct fib_rule *rule;



nlmsg_failure:

rtattr_failure:

	skb_trim(skb, b - skb->data);

	return -1;

	if (!list_empty(&fib4_rules)) {

		pos = fib4_rules.next;

		if (pos->next != &fib4_rules) {

			rule = list_entry(pos->next, struct fib_rule, list);

			if (rule->pref)

				return rule->pref - 1;

		}



/* callers should hold rtnl semaphore */



static void rtmsg_rule(int event, struct fib_rule *r)

{

	int size = NLMSG_SPACE(sizeof(struct rtmsg) + 128);

	struct sk_buff *skb = alloc_skb(size, GFP_KERNEL);



	if (!skb)

		netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, ENOBUFS);

	else if (inet_fill_rule(skb, r, 0, 0, event, 0) < 0) {

		kfree_skb(skb);

		netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, EINVAL);

	} else {

		netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV4_RULE, GFP_KERNEL);

	}



	return 0;

}



int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)

static struct fib_rules_ops fib4_rules_ops = {

	.family		= AF_INET,

	.rule_size	= sizeof(struct fib4_rule),

	.action		= fib4_rule_action,

	.match		= fib4_rule_match,

	.configure	= fib4_rule_configure,

	.compare	= fib4_rule_compare,

	.fill		= fib4_rule_fill,

	.default_pref	= fib4_rule_default_pref,

	.nlgroup	= RTNLGRP_IPV4_RULE,

	.policy		= fib4_rule_policy,

	.rules_list	= &fib4_rules,

	.owner		= THIS_MODULE,

};



void __init fib4_rules_init(void)

{

	int idx = 0;

	int s_idx = cb->args[0];

	struct fib_rule *r;

	struct hlist_node *node;



	rcu_read_lock();

	hlist_for_each_entry(r, node, &fib_rules, hlist) {

		if (idx < s_idx)

			goto next;

		if (inet_fill_rule(skb, r, NETLINK_CB(cb->skb).pid,

				   cb->nlh->nlmsg_seq,

				   RTM_NEWRULE, NLM_F_MULTI) < 0)

			break;

next:

		idx++;

	}

	rcu_read_unlock();

	cb->args[0] = idx;

	list_add_tail(&local_rule.common.list, &fib4_rules);

	list_add_tail(&main_rule.common.list, &fib4_rules);

	list_add_tail(&default_rule.common.list, &fib4_rules);



	return skb->len;

	fib_rules_register(&fib4_rules_ops);

}



void __init fib_rules_init(void)

void __exit fib4_rules_cleanup(void)

{

	INIT_HLIST_HEAD(&fib_rules);

	hlist_add_head(&local_rule.hlist, &fib_rules);

	hlist_add_after(&local_rule.hlist, &main_rule.hlist);

	hlist_add_after(&main_rule.hlist, &default_rule.hlist);

	register_netdevice_notifier(&fib_rules_notifier);

	fib_rules_unregister(&fib4_rules_ops);

}